[memmap] Rename addr/last fields to min/max for clarity

Use the terminology "min" and "max" for addresses covered by a memory
region descriptor, since this is sufficiently intuitive to generally
not require further explanation.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/memmap_settings.c

@@ -175,9 +175,9 @@ static int memmap_settings_fetch ( struct settings *settings,
 
 		/* Extract results from this region */
 		if ( include_start ) {
-			result += region.addr;
+			result += region.min;
 			DBGC ( settings, "MEMMAP %d start %#08llx\n", index,
-			       ( ( unsigned long long ) region.addr ) );
+			       ( ( unsigned long long ) region.min ) );
 		}
 		if ( include_length ) {
 			result += memmap_size ( &region );